The present invention relates to new and useful improvements in windmills for harnessing wind energy and, more particularly, to a modular windmill installation for transforming the energy of wind currents into a usable rotational force and for storing any excess energy generated by the windmill installation.
Windmills and other wind-driven power generating apparatus have long been known in the art. Such apparatus is exemplified by the windmills and wind motors disclosed, for example, in U.S. Pat. Nos. 1,234,405; 2,431,111; and 4,134,707. One type of windmill apparatus is conventionally constructed with a plurality of vertically stacked, individual segments of two or more wind wheels or wind rotors, each of which is adapted to be drivingly connected to a common output drive shaft. By increasing the number of individual segments connected to the drive shaft, the greater the driving force or torque and, thereby, the greater the power that can be generated with the apparatus.
The wind motor apparatus of U.S. Pat. No. 2,431,111 includes a manually-operated, jaw-type positive clutch for selectively connecting and disconnecting wind wheel segments in series depending on the magnitude of the wind force or the output power desired. In this way, the apparatus is said to be adapted for operation in low or high wind currents or for operating, for example, more than one power consuming mechanism.
U.S. Pat. Nos. 1,234,405 and 4,134,707 both disclose wind turbine apparatus which comprise discrete wind wheel segments joined together in a vertical stack to form a unitary wind turbine. As the segments are added, they are rigidly interconnected to either the drive shaft or to each other from the lowermost to the topmost segment.
One disadvantage of the windmills and wind turbine apparatus of the type according to the aforementioned prior art patents is that no provision is made for the continued generation of power by the apparatus in the event of random failure of one or more of the individual wind wheel segments.
It is also known to employ a windshield or casing for covering a portion of the blades of a wind wheel rotor so that the wind stream impinges on only those blades which are properly oriented with respect to the wind direction. U.S. Pat. Nos. 1,460,114 and 2,059,356, for example, disclose wind wheels having shields mounted for rotation about the periphery of a wind rotor. Wind vanes connected to the shields are said to cause the shields to respond to wind direction in a manner to present the most favorable rotor aspect to the wind stream, as well as to shield the blades from the force of the wind when the velocity thereof becomes sufficiently high to cause damage to the wind wheel installation.